Patent GB-1428011-A (GB)
Title: Document feeding device
IPC: B41F17/14
Filed: 1973-08-30
Abstract: 1428011 Feeding sheets AES TECHNOLOGY SYSTEMS Inc 30 Aug 1973 [1 Sept 1972 24 Jan 1973] 40988/73 Heading B8R Pile supports.-Sheets are supported for separation from the bottom of a pile in a hopper comprising an inclined base surface 16, Fig. 2, a front wall 18 and means 20 to apply pressure to the rear of the pile. Sheet separators.-The bottom sheet is separated from the pile and fed out beneath the wall 18 by a resilient rubber roller 32 having projections 34. Preventing double feed.-Sheets separated pass between the roller 32 and a pair of elements supported on a bracket 36 and serrated on their upper surfaces. If two sheets are fed together, the lower sheet is held back by the serrated surfaces. Sheet forwarders.-Separated sheets are for-  warded by a plurality of transversely spaced  belts 50 and by a roller 66 through printing  couples 26, 27, passing over a vacuum chamber 54 whose upper surface is perforated between the belts, and thence to a copying machine. In another form, Fig. 9, not shown, the vacuum chamber is omitted and the sheets are forwarded between upper and lower sets of belts 50. In another form Fig. 10, the first printing couple 72, 74 is located upstream of the belts 50, and sheets are conveyed through the couple by further belts 401. Sheet guides.-Sheets leaving the printing couple, 72, 74, Fig. 10, are guided to the belts 50 by guide plates 407, 408. Registering sheets.-Each sheet is fed against a gate 24 comprising a plurality of transversely spaced fingers 62 mounted upstream of the pressing couples on a shaft 60 so as to register the leading edge, whereafter the shaft is rotated to raise the fingers to allow the sheet to proceed. In other forms, Fig. 9 (not shown) and 10, the gate is between the couples. Controlling mechanism.-The belts 50, roller 66 and impression rollers 72, 90 are driven continuously by a motor 100. The roller 32 is driven through a clutch controlled by a solenoid. The printing heads 74, 94 are driven through friction clutches and are held stationary by latches controlled by solenoids. A switch 234 prevents operation of the roller 32 when the hopper is empty. Rotation of the roller 32 is initiated by closing a manual switch which establishes a holding circuit. When a sheet engages a director 232, a switch 230 is reversed to stop the roller 32 and energize a time delay relay, adjustable according to sheet size and desired spacing between sheets, which opens the gate 24 after the sheet has been registered. Opening of the gate closes a switch which restarts the roller 32 and rotates the printing head 74, a cam on the shaft of which closes a switch to rotate the printing head 94. The gate 24 having closed after releasing a sheet the sheet after being printed engages a detector 301 to actuate a switch 300 and prevent the gate opening again until the sheet has passed the detector 301. Where the gate is between the printing couples, the switch 230 actuates the first couple, and the gate-actuated switch actuates the second couple. In the form shown in Fig. 10, the detector 500, corresponding to 300, 301, is photoelectric.